CAMBRO-SILURIAN MICRO-PAL iEONTOLOGY. 39 



St. Andiews, Manitoba, where the type specimen was collected by 

 Dr. R. Bell in 1880. The Minnesota examples are from the Trenton 

 shales at Minneapolis, Minn. 



Stictopora or Rhinidictya, sp. indt. 



A fragment of a species of this genus occurs among the material col- 

 lected by Mr. T. C. Weston at Stony Mountain in 1887. It is clearly 

 identical with the species found near the top of the Hudson River or 

 Cincinnati group at several localities in Ohio. The specific relation of 

 these specimens is as yet doubtful. Careful comparisons with S. 

 Mcholsoni, Ulrich, a common species from the Birdseye limetone of 

 Kentucky and elsewhere, and >S^. mutabilis, Ulrich, from the Trenton 

 shales of Minnesota, and with another form (Ptilodictya parallela, 

 James,) occurring rather rarely in the Utica horizon or lower beds 

 of the Hudson River group, being necessary before they can be dis- 

 posed of in a final manner. These species are all closely related to 

 each other and to S. fenestrata, Hall, the type of Stictopora, as re- 

 woked by me in the 14th Ann. Rep. Geol. Surv. Minn., 1886,* as well, 

 and it is not possible in the present state of our knowledge to say what 

 changes would result fi-om a monographical study of the genus. In 

 fact, the whole of the paliBozoic bifoliate Bryozoa are sadly in need 

 of revision. It is therefore deemed advisable to refer to the species in 

 question as above. 



That the form may be recognized by others, it is well to mention 

 that the general aspect of the surface agrees very closely with that of 

 S. Nicholsoni {Rhinidictya Nicholsoni, Ulrich), Jour. Cin. Soc. Nat. Hist., 

 Yol. v., page lYO, pi. 8, figs. 6-6b. The branches are 2*0 to 2-5 mm. 

 wide, having nearly parallel margins, fourteen to eighteen rows of 

 zooecia, with thirteen in five mm. measuring longitudinally. 



* Since the publication of Vol. VI. Pal. N, Y.. 1887, in which Prof. Hall gives S. eleqanttda 

 as the type of his genus, I have begun to realize that the claims of S. fenestrata to that distinc- 

 tion are not likely to naeet with general approval. In that case, Rhinidictya might .stand. The 

 only objection to reinstating that generic name arises from the fact that in 1848, d'Orbigny pro- 

 posed SnXcopora for Sfritopora fenestrata, which species is most probably congeneric with Rhini- 

 dictya Nicholsoni. However, I for one. am not inclined to accept Sidcopora, nor Suhrctepora and 

 Ennallopora, all founded by the same author upon nothing more than Hall's original figures and 

 descriptions in Vol. I. Pal. N. Y. d'Orbigny's descriptions of these genera are not only vague 

 and inadequate, but the very points mentioned by liim are either not peculiar to the genera he 

 sought to establish, or they actually do not exist in the original of the figures upon which he 

 relied. Moreover, none of Ihese generic names have been recognized by subsequent worker* in 

 the field, and I fail entirely to see what good could result from bringing them forward now after 

 lying dormant for so many years. It would only add confusion to already complicated questions 

 of synonymy. 



November, 1889. 2 



